Overview:The rough-skinned newt looks harmless enough but is, in fact, packed full of one of the most potent neurotoxins known to man. Find out how an evolutionary arms race has pushed these mild-mannered critters to the extremes of toxicity and how evolutionary biologists have unraveled their fascinating story.

Author/Source:UC Museum of Paleontology

Grade level:13-16

Time:45 minutes

Teaching tips:Use this resource to relate evolutionary concepts to the nature and process of science (or get more suggestions for incorporating evolution throughout your biology syllabus). This case study includes entertaining cartoons. You might cap study of this article by showing students a part of PBS's Evolution video that highlights this arms race: http://www.pbs.org/wgbh/evolution/library/01/3/l_013_07.html

There is a fit between organisms and their environments, though not always a perfect fit.

Evolution results from natural selection acting upon genetic variation within a population.

Natural selection and genetic drift act on the variation that exists in a population.

Inherited characteristics affect the likelihood of an organism's survival and reproduction.

Over time, the proportion of individuals with advantageous characteristics may increase (and the proportion with disadvantageous characteristics may decrease) due to their likelihood of surviving and reproducing.

Traits that confer an advantage may persist in the population and are called adaptations.

Depending on environmental conditions, inherited characteristics may be advantageous, neutral, or detrimental.